I am in the process of replacing the inboard engine mount stringers on my 1975 F32. The stringers run from the transom to galley bulkhead and are approximately 152" long x 2 1/2" wide and range from 12" to 9" high. In addition, I will be replacing the vertical supports on the transom which are 26" long x 2 1/2' wide by 3" high as well as the deck floor support ridge on top of the vertical supports attached to the transom. The floor support ridge is 132" long by 1" thick and varies in width from 3 1/2' to 4" which support the cockpit teak deck. There are also dry rotted sections in the plywood bulkhead sections below the sliding glass door which I also plan to replace. My plan is to completely cut out all of the above and glass all replacements to the hull directly. My questions relate to the replacement materials.
Stringers:
a) What is the best material to fabricate the new stringers with, original solid wood (suggestions on type) or marine plywood frabricated stringers.
b) if the suggestion is plywood fabrication, what type and grade of plywood should be used. Is pressure treated plywood an option?
c) some areas of the stringers do not appear to be glassed directly to the hull should this be replicated or should they be glassed directly to the hull?
d) Some areas where the vertical transom supports meet the stringers, where the stringers pass through the bulkhead and where gas tank supports meet the stringers are bare wood. Also some of the drain openings in the stringers were not completely encapsulated with fibreglass. These areas caused water intrusion points and resulted in dry rot. Should these areas on the new stringers and supports be completely encapsulated with glass and epoxy when installed?
Bulkhead:
a) Can pressure treated plywood be used instead of marine plywood? Will epoxy stick to pressure treated plywood. I replaced a section of this bulkhead with marine plywood 10 years ago and there is rot in the same place.
Vertical Supports:
Same as stringer questions
Deck Support Ridge
a) What replacement material do you recommend assuming the thickness of the old core is 1"? Can engineered wood materials (ie. Trex) be used? Are these materials strong enough and will epoxy and glass adhere to them?
1975 F32 Stringer Replacement
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